Open relationships

So I grew up in a pretty small unaccepting county, since then it's been about a year and I moved to a big city and have been dating my first boyfriend for about the same time ( a year ) and we are very happy! Life's good! However, I've noticed that most all ( not all all but more than not ) gay relationships are open. I have 100% no interest in that. I'm very happy there are people who can function in that type of relationship but I am not one of them. and neither is my boyfriend from what he's told me. But I have noticed there is this weird push from our gay friends to try the whole open thing. A lot of gay couples I've encountered almost act offended when I say we are exclusive with eachother. Almost like it's taboo. I really feel super weird about this, even if my boyfriend wanted me to sleep with other guys i don't know that I myself could do it. I love when we both come home after a busy day ( he's a nurse and i work in theatre professionally ) and have eachother. In my field there are a shit ton of attractive gay guys but I have never once had an urge to even flirt with them, I mean yes I find them attractive but in a friendly way? I just don't want to feel forced to conform to this lifestyle when personally I've seen most all of these relationships fail because of the uncomfortable situations this type of relationship brings. A lot of our gay friends have split up or had huge fights and I'm not bragging in any way but my boyfriend have really no complications. We fit eachother very well. Anyway the point I'm trying to get too is, is it weird to want to stay traditional? I hate that word but in this case I'm using it. I don't want to share, and neither does my man, is that wrong??? Why is it so taboo to be happy with one person?